In late 2012, Governor Snyder signed a law making Michigan - the birthplace of the UAW - a so-called right-to-work state. The new law allows people in unionized workplaces to opt out of paying union dues.

Then, in February of 2014, the union lost a key vote to organize more than 1,500 blue-collar employees at Volkswagen's Chattanooga plant.

UAW leaders appeared confident, at first, that the vote would go their way.

But prominent Republican politicians, along with billionaire businessmen Charles and David Koch waged a fierce battle of money and words to oppose the campaign, including threats that a successful union drive could mean no new products coming to the plant.

The union vote was 53% against, to 47% in favor.

Now, the union says it will set up a local on its own, and workers can sign up voluntarily. The hope is, if enough workers join, Volkswagen and the UAW can set up a a German-style works council, where workers and management cooperate on many issues to do with factory work rules, quality, and productivity.

The UAW has about 390,000 members now. That's a few thousand more than a few years ago - but far below its historic high of more than a million and a half.

During his tenure, former UAW President Bob King said the union has "no future," in the U.S. unless it can expand its representation of workers at foreign-owned plants in the U.S. - most of which are in right-to-work states in the south.